Breakfast cereals and snacks are generally prepared by forming a dough from flour and water, cooking the dough and shaping the cooked dough into pieces by extruding, cutting or flaking. Generally, expanded or puffed cereals have little or no added fat and are not chemically leavened. Puffed or expanded cereals generally have a low density and are very porous due to the cell structure formed by flashing off moisture at the extruder die. The porous characteristic of puffed cereals results in a cereal which readily absorbs liquids and quickly becomes soggy in milk. Flaked cereals, such as corn flakes, are generally of higher density than puffed cereals. These flaked cereals similarly tend to have a relatively short bowl life and become soggy within a few minutes after immersing in milk. The tendency of conventional cereal formulations to become soggy very quickly when immersed in milk has typically resulted in limited consumer appeal of the products and encouraged efforts to find suitable methods of extending the bowl life of ready-to-eat cereals.
Conventional cookie formulations become soggy very quickly when immersed in milk and tend to disintegrate completely. Generally, expanded or puffed cereals become soggy in milk in a few minutes but still retain some structural integrity such that the cereal pieces do not completely disintegrate. In contrast, cookie formulations absorb milk quickly and disintegrate.
Conventional cookie production generally involves preparing a farinaceous dough having a high fat or shortening content. The water content is usually rather low compared to conventional cereal compositions for producing breakfast cereals. The amount of water added to cookie doughs is usually only that amount needed to make the dough machinable by commercial machines. The high fat content and the leavening of the cookie dough may contribute to the crumb-like structure, texture and flavor of cookies. The high fat or shortening content of cookies is one characteristic which distinguishes cookies from crackers and expanded or puffed starch-based products.
Although the reasons are not completely understood, the high fat content of the cookie formulation tends to correlate to the short bowl life and short disintegration time of cookies when immersed in milk. The short bowl life of cookies may be due in part to the leavened crumb-structure of cookies which absorb milk faster than the expanded cellular structure of puffed cereals. It has generally been observed that as the fat content increases in the cookie formulation, the disintegration time of the baked cookie decreases. This characteristic has limited the successful use of cookie formulations in producing a ready-to-eat breakfast cereal which has an acceptable texture and bowl life in milk.
Efforts to improve the bowl life of breakfast cereals prepared from extruded and expanded cereal doughs and from baked cookie formulations have generally experienced only moderate success. In many instances the bowl life of expanded cereals is enhanced by providing a heavy sugar coating on the cereal pieces followed by a coating of a vegetable gum. Other methods to extend bowl life include providing a coating of fat or oil on the cereal. In addition to fats and oils, other hydrophobic components, such as waxy materials, have been used as coatings or additives in attempting to extend bowl life.
One method of extending the bowl life of cereals and snack foods is disclosed in U.S. Pat. No. 3,769,438. The disclosed method applies a coating of a bowl-life-extending syrup on conventionally prepared ready-to-eat breakfast cereals, such as puffed wheat, puffed rice and puffed corn. The syrup is prepared by initially forming a heated aqueous solution of a hexitol, such as sorbitol or mannitol. A fat or oil is then added to the heated syrup and dispersed homogeneously. The ratio of hexitol to fat is disclosed to be 0.03:2.
In the method disclosed in U.S. Pat. No. 3,769,438 emulsifiers are included in the syrup to disperse the fat or oil. The aqueous solution is heated to 180.F before adding fat. The cereal is coated by adding the puffed cereal to a tumbling coating pan and slowly adding the hot syrup to the tumbling cereal. The composition of the coating on the finished cereal product is reported to be made up of 0.5% to 15% hexitol, 5% to 20% fat, with the remainder being made up of sweeteners, flavors, salt and seasonings.
Another example of an effort to improve bowl life is disclosed in U.S. Pat. No. 4,588,596. A ready-to-eat cereal is disclosed as being produced from a cookie dough which is formed into bite size pieces. The disclosed cookie formulation includes at least 40% of flour or other cereal grain, 3% to 17% fat, and 20% to 50% sugar. The bowl life of cereals prepared from the cookie formulation are reported to be improved by incorporating a waxy material from a metallic fatty acid salt, such as zinc stearate. The fatty acid salt is reportedly effective when incorporated into the cookie formulation or when applied as a coating. When used as a coating, the cereal pieces are warmed and dusted with a powder of the fatty acid salt. The coated cereal pieces are then placed in an oven to melt the coating and then redusted and heated a second time. The metallic fatty acid salt is reported to provide a bowl life of 4 minutes or more.
U.S. Pat. No. 4,350,714 relates to a method of producing an expanded cereal containing high levels of corn bran which reportedly has an enhanced bowl life. The ingredients are prepared in a cooker-extruder under high pressure and temperature. The cooked cereal composition is extruded under high pressure to form an expanded product. It is reported that corn bran ground to a fineness of 40 mesh or finer prevents extruder surging and results in improved bowl life characteristics compared to commercially prepared ready-to-eat cereals containing wheat bran. The primary starch-containing ingredient includes oats, corn, wheat flour, rice, sorghum, soya, tapioca, waxy maize and other cooked cereal grains.
Another method of producing a puffed cereal product is disclosed in U.S. Pat. No. 2,954,296. This method produces an expanded, puffed cereal by adding ingredients to a cooker extruder and extruding under elevated pressure and temperature. The method includes combining small percentages of pregelatinized starch-containing materials along with the uncooked farinaceous material. The use of the pregelatinized starch-containing materials is reported to provide adequate elasticity to the dough such that adequate expansion takes place at the puffing pressures. The expanded product is reported to have a more uniform vesicular internal structure and a comparatively softer external shell. The strength of the cell walls and the size and distribution of the cell wall cavities are said to produce a product having a high resistance to chewing and which will not decompose on hydration in milk to a mushy condition. The pregelatinized starch is disclosed as being starch from any cereal or fiber. The disclosed starches include pregelatinized corn, waxy maize, tapioca and potato.
In the process of the present invention, ready-to-eat cereals are produced by forming a cookie dough and shaping the dough into bite size pieces and baking the pieces. The cookie dough used to produce the ready-to-eat cereal includes an effective amount of one or more starch-based bowl life extenders to provide an improved bowl life to the baked cereal pieces.